The present invention relates to a workpiece transport apparatus which is employed for transferring a workpiece from one operating or work station to another work station in response to the operation of at least one of said work stations. One work station may, for example, be a pressure die casting machine and the other work station may be a trimming press. The copending application describes an apparatus in which the transport mechanism arranged between a pressure die casting machine and a trimming press, comprises a transport arm which is movable about a horizontal axis or an axis which is substantially horizontal. One end of the transport arm is journaled to said axis and the other free end of the transport arm has secured thereto a tilting arm which is movable by means of a parallel guide mechanism. The tilting arm carries workpiece gripper means and the drive means for the transport arm are arranged coaxially on said axis about which the transport arm is tiltable. If desired, the tilting arm drive means may also be arranged on said tilting axis of the transport arm.
Pressure die casting machines are equipped with one or more ejector devices for facilitating the removal of a die cast workpiece from the machine. Difficulties are encountered in removing the workpiece from a die because the cast material tends to form a burr, especially along the interface between two halves of a die. In order to reduce the burr formation it is known to employ mold dressing means. However, this has the disadvantage that a cast workpiece may drop to the ground immediately, even before the gripping means become effective, especially where mechanical gripping means are employed for the transfer of the workpiece. Thus, it has been suggested to grip a workpiece while it is still in the die, that is, prior to its ejection. To this end workpieces have been provided with a lug formed as part of the workpiece during the casting. The gripping mechanism is then able to grip the lug prior to the ejection of the workpiece from the mold. However, in order to assure that the gripping device can always precisely grip the lug, it is necessary that the latter will always be precisely in the same position. This requirement has not yet been satisfactorily met by the prior art. However, it is important that a precisely determined discharge position for the workpiece is assured at all times in order not only to facilitate the workpiece removal, but also to correctly position the workpiece in a further work station such as a trimming press. The precise positioning is also necessary for the checking of certain surface areas of the workpiece. Such surface area checks are employed for controlling the correct and complete removal of a workpiece from the die.